Land subsidence resulting from groundwater extractions is a global phenomenon adversely affecting many regions worldwide. Understanding the governing processes and mitigating associated hazards ...require knowing the spatial distribution of the implicated factors (piezometric levels, lithology, ground deformation), usually only known at discrete locations. Here, we propose a methodology based on the Kriging with External Drift (KED) approach to interpolate sparse point measurements of variables influencing land subsidence using high density InSAR measurements. In our study, located in the Alto Guadalentin basin, SE Spain, these variables are GPS vertical velocities and the thickness of compressible soils. First, we estimate InSAR and GPS rates of subsidence covering the periods 2003-2010 and 2004-2013, respectively. Then, we apply the KED method to the discrete variables. The resulting continuous GPS velocity map shows maximum subsidence rates of 13 cm/year in the center of the basin, in agreement with previous studies. The compressible deposits thickness map is significantly improved. We also test the coherence of Sentinel-1 data in the study region and evaluate the applicability of this methodology with the new satellite, which will improve the monitoring of aquifer-related subsidence and the mapping of variables governing this phenomenon.
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view observatory sensitive to 500 GeV-100 TeV gamma-rays and cosmic rays. It can also perform diverse indirect ...searches for dark matter annihilation and decay. Among the most promising targets for the indirect detection of dark matter are dwarf spheroidal galaxies. These objects are expected to have few astrophysical sources of gamma-rays but high dark matter content, making them ideal candidates for an indirect dark matter detection with gamma-rays. Here we present individual limits on the annihilation cross section and decay lifetime for 15 dwarf spheroidal galaxies within the field of view, as well as their combined limit. These are the first limits on the annihilation cross section and decay lifetime using data collected with HAWC. We also present the HAWC flux upper limits of the 15 dwarf spheroidal galaxies in half-decade energy bins.
Hexacene and larger fused rings remain elusive targets for chemists. Here, we report a hexacene-like molecule containing six linearly fused rings, specifically a pentacene molecule fused with a ...terminal thiophene ring, pentaceno2,3-bthiophene. It can be purified and isolated as a purple-black powder at ambient conditions. This molecule has a low HOMO−LUMO gap of 1.75 eV in o-DCB and an optical band gap of 1.58 eV in thin film. Top contact organic thin film transistors (OTFTs) were made, and atomic force microscopy (AFM) reveals a dendritic thin film growth characteristic of pentacene. An OTFT mobility of 0.574 cm2/V s was measured for pentaceno2,3-bthiophene under nitrogen.
Medusozoans are diverse in species number (4100) and life stages and are of ecological and social importance worldwide. However, studies of medusozoans in the Mexican Pacific (MP) are limited and ...scattered. Given that its maritime (2,320,380 km
2
) and coastal (7828 km) regions are the most extensive in Mexico, as well as its geomorphological and ecosystem complexity, the medusozoan fauna of the MP needs better documentation. To that end, this work summarises medusozoan diversity data of the MP based on a review of refereed publications (1897-2023) and the examination of recently collected specimens, field observations, and photographs (2015-2022). Information gathered from the literature search and the collections was compiled into an annotated list of species. As a result, 423 accepted medusozoan species were found in the MP, corresponding to 10% of the 4100 medusozoan species known worldwide. This study highlights three important decades of published work: taxonomic works in the 1930s, ecological works in the 1980s, and recognition of biodiversity under multidisciplinary works in the 2010s. Of the taxa collected in the present work, Cirrholovenia sp., Linuche sp., and Monotheca flexuosa are new records for the MP. Furthermore, Hydrocoryne sp. and Coryne pusilla are new records for the Gulf of California.
The study results describe the hydrogeochemical and the hydrodynamic characterization, and the evolution compounds in the water in the Nichupté Lagoon System (NLS). This is the most representative ...lagoon of Quintana Roo State and hosts the Natural Protected Area “Manglares de Nichupté” and borders the Punta Cancún-Punta Nizuc National Park. Sampling was performed during rainy and cold-front seasons to asses the distribution and variability of temperature, pH, dissolved axygen salinity, nutrients and major elements. Significant differences were detected for temperature and salinity but not for dissolved oxygen between the seasons. The dissolved oxygen values have considerably diminished in a decade. NOx and PO4 concentrations were high, and did not show significant differences between seasons. NH4+ concentration was an order of magnitude higher in the rainy season. Two types of water occur in the study area (Cl) and (Cl-SO4-Na-Ca-Mg). A strong predominance of Na-Cl, classifies the lagoon system as a brackish lake. Evaporation was the dominant process and the lagoon behaves like a salty lake, with an evolution in the chemical composition of the water, which became enriched in calcium during the cold-front season, and in sulfates during the rainy season. No precipitation of calcite or gypsum was identified, but this could occur during the cold fronts due to the geochemical evolution observed in the Spencer diagram. Nutrient concentrations have increased in ten years, but some are still below Mexican water quality criteria (CE-CCA-001/89). Some sites present high nutrients concentrations like Bojorquez lagoon sites. The results obtained underline: a) high temperature records vis-à-vis of previous studies measurements (historical records), b) decreasing dissolved oxygen concentrations, c) increasing NO3− and PO43− concentrations. These factors combination shows eutrophication signs that should already be taken as an alert. The circulation of the water in the two analyzed periods was qualitatively similar but the magnitudes of the currents were remarkably different between each other. The rainy season (August 2015) showed near-coastal mean currents of magnitude ∼2–3 cm s−1, while the cold-front season (March 2016) showed mean currents about twice stronger (∼5–6 cm s−1). The circulation pattern result in relatively short residence times of the water bodies of the Lagoon System, with values from 3 to 6 weeks in the rainy season; these values can be decreased by 30–50% in the cold-front season.
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•The dominant process is the evaporation, two water types (Cl−) and (Cl−-SO42--Na+-Ca2+-Mg2+).•Water is enriched in Ca2+ (cold-front season), and in SO42− (rainy season).•High temperature records vis-à-vis of previous studies measurements.•Decreasing dissolved oxygen concentrations, increasing NO3−, PO43− concentrations.•Circulation qualitatively similar in both seasons but magnitudes remarkably different.
Few studies identify potential hazards affecting canyoning. This activity has an increasing number of practitioners, and hence, a greater number of people are affected by potential natural hazards. ...Mountain rivers are located in places subject to several hydrological hazards; the risks are mostly connected with floods produced by intense storms or dam operation, but changes in hydrological factors may alter the usual basin behavior given even moderate or less severe storms. Data about flood events and the peak discharge of the 2017 flood in the two studied canyons were collected by means of a quick field survey of water levels after the flood, hydrological modeling, and soil analysis. The present research shows the dramatic consequences of a two-year return period storm affecting a guided group of canyoneers. A previous wildfire changed the soil, leading to hydrophobic conditions and increasing the flood effects. Peak discharge increased from 2 m3 s−1 in normal conditions to 12 m3 s−1 under a hydrophobic regime related to wildfire occurrence; moreover, a reduction in the time of concentration also occurred, pointing to a more powerful and dangerous flood event. In this paper, some hydrological recommendations are highlighted that will be helpful in recreational canyoning management, leading to safer practice.
We present results from daily monitoring of gamma-rays in the energy range from ∼0.5 to ∼100 TeV with the first 17 months of data from the High Altitude Water Cherenkov (HAWC) Observatory. Its wide ...field of view of 2 steradians and duty cycle of % are unique features compared to other TeV observatories that allow us to observe every source that transits over HAWC for up to ∼6 hr each sidereal day. This regular sampling yields unprecedented light curves from unbiased measurements that are independent of seasons or weather conditions. For the Crab Nebula as a reference source, we find no variability in the TeV band. Our main focus is the study of the TeV blazars Markarian (Mrk) 421 and Mrk 501. A spectral fit for Mrk 421 yields a power-law index and an exponential cut-off TeV. For Mrk 501, we find an index and exponential cut-off TeV. The light curves for both sources show clear variability and a Bayesian analysis is applied to identify changes between flux states. The highest per-transit fluxes observed from Mrk 421 exceed the Crab Nebula flux by a factor of approximately five. For Mrk 501, several transits show fluxes in excess of three times the Crab Nebula flux. In a comparison to lower energy gamma-ray and X-ray monitoring data with comparable sampling, we cannot identify clear counterparts for the most significant flaring features observed by HAWC.
Massive accumulations of pelagic species of
Sargassum
have generated recent social, economic and ecological problems along Caribbean shores. In the Mexican Caribbean, these events have prompted the ...study of diverse biological and ecological aspects of these macroalgae. However, studies on their associated biota, including Hydrozoa, remain scarce. This research provides important species observations in an area where data is lacking. The occurrence and percent cover of hydroids on
Sargassum
thalli collected on the beach at Puerto Morelos, Quintana Roo, Mexico from April 2018 to March 2019 was studied. Three pelagic species and morphotypes of
Sargassum
from this area were analyzed:
Sargassum fluitans
III,
S. natans
I and
S. natans
VIII, as well as a benthic species,
S. polyceratium
var.
ovatum
. A total of 14 taxa of hydroids, belonging to the superorders “Anthoathecata” and Leptothecata, were identified. In our study, more hydroid taxa were observed on axes of the different species of
Sargassum
than on leaves or aerocysts. In general, the greatest species richness of hydroids was observed from February to April. Results show that live hydrozoans attached to pelagic
Sargassum
are transported into the area. This should be considered in future management measures that address the recurring coastal abundance of
Sargassum
and its associated biota in the Caribbean region.
Access to digital technology and software allows the production of a significant amount of biodiversity data, including citizens' species records, combined with field monitoring and standardized ...surveys, which are valuable to biological sciences; these data can help to know the distribution of organisms like medusozoans. We compiled records of the presence of Porpita porpita from open-access databases, scientific articles, and field observations to know their current distribution on the Mexican Atlantic for the first time. The yearly records of P. porpita increased over time, adding up to 22 records, of which 18 were assigned to citizen science. Most records correspond to 2011-2022, from April to May, and the Veracruz and Quintana Roo states. The records of the species in warm months and states with long shores can be related to an increase in touristic activities and observations by citizens. On the Mexican Atlantic, it is suggested that the use of digital technological devices under citizen science practices for recording P. porpita and its compilation in open-access databases acts as the principal method for tracking the distribution of this species. This work evidenced the need for a solid research framework of knowledge for P. porpita in the Mexican Atlantic, and future research could combine citizen science records and fieldwork records and improve the relationship between biological and oceanographic data to understand their spatial-temporal distribution patterns.
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![Pentaceno[2,3-b]thiophene, ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0002-7863/small "Pentaceno[2,3-b]thiophene, a Hexacene Analogue for Organic Thin Film Transistors")
